Critical survey of the present stand of the production of perfect stage of organs of fructification in dermatophytes

Summary Very little progress had been made on the question whether organs of higher fructification occur in dermatophytes. Only two significant studies can be noted. One was the elaboration of the hypothesis byMatruchot &Dassonville that dermatophytes because of morphological similarities with certain fungi (Myxotrichum, Gymnoascus, Arachniotus) belong with them to the Gymnoascaceae. However, this generalization was unwarranted, since their hypothesis was based on a single strain of a dermatophyte, designated by them as Trichophyton, sp. without the species having been more closely determined. Moreover, they did not produce any evidence for their generalization that all dermatophytes should, or necessarily must belong to the Gymnoascaceae. Finally,Matruchot &Dassonville had never seen either pycnidia or perithecia in their cultures. To say the least, their hypothesis, whether right or wrong, must await further demonstrations that pycnidia and/or perithecia do exist in the dermatophytes.The only apparently successful attempt at solving the question of the existence of higher organs of fructification in dermatophytes has been made byNannizzi. His findings must be considered valid, unless duplications of his experiments would prove to the contrary. However, the same objection has to be made against his generalization as was raised against the generalization ofMatruchot &Dassonville. This is that ALL dermatophytes must necessarily belong to the Gymnoascaceae.Nannizzi succeeded in producing pycnidia only in the form-genusTrichophyton, in the speciesTr. mentagrophytes (Ch. Robin, 1853) andTr. equinum Matruchot. He also was successful in his endeavor in the form—genusAchorion, in the speciesAchorion gypseum Bodin. However, his attempts to produce higher organs of fructification inMicrosporon lanosum Sabouraud and inAchorion Quinckeanum Zopf failed.

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Zusammenfassung Versuche, betreffs des gegenwärtigen Standes der Fruchtkörperproduktion in Dermatophyten, die sich nun auf sechs Jahrzehnte erstrecken, sind kritisch beleuchtet worden.Es konnte nur ein einziger, anscheinend erfolgreicher Versuch verzeichnet werden, der vonNannizzi, 1926. Mit seiner speziellen Technik, indem er Dermatophyten auf natürlichen Nährböden (Federn, Leder, Knochen, Haare) züchtete, war es ihm gelungen, Pykniden in der Form-GattungTrichophyton, in den ArtenTr. mentagrophytes (Ch. Robin, 1853) undTr. equinum Matruchot hervorzurufen. In der Form-GattungAchorion sind Pykniden in der ArtAchorion gypseum Bodin produziert worden in einem Nährboden von Waldboden gemischt mit Stückchen von altem Leder. Jedoch sind seine Versuche, Pykniden inMicrosporon lanosum Sabouraud und inAchorion Quinckeanum Zopf hervorzurufen, fehlgeschlagen.